One of the best-kept fitness secrets is that you don’t have to spend hours a day, every day, in the gym to see results. To make the most of the time you have, many experts recommend metabolic conditioning — a workout protocol designed to maximize the potential of your body’s energy systems, resulting in a stronger, fitter, and faster you. And the workouts last no more than 30 minutes, tip to tail.
Metabolic conditioning, or metcon, aims to increase the efficiency of your three energy systems: adenosine triphosphate–creatine phosphate (ATP-CP), glycolytic, and oxidative. These systems work together to fuel activities of varied intensities or effort. (For more on these systems, see “All About Your Metabolic Energy Systems.”)
The magic of metcon lies in the timing of interval workouts that stimulate one energy system to work harder than the other two. The goal is to balance adequate rest periods with movements of varying intensities, so you’re ready to get moving again once the timer beeps. This work–rest structure requires a lot of effort in a short period of time.
Targeting each energy system in two or three discrete sessions spread throughout the week makes metabolic-conditioning workouts “physiologically smart,” explains Tineile Heiler, creator of Life Time’s Alpha Metcon program. This avoids the pitfall of workouts designed to make you feel like you’ve been run over by a steamroller — and potentially so exhausted or discouraged that you quit.
Perhaps the most attractive aspect of metabolic conditioning is approachability: Timed intervals allow you to move at your own speed. Whether you’re an exercise newbie or a seasoned athlete, you can go at a pace that feels challenging for you.